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Explorer
Posts: 17
Registered: ‎11-15-2013
Accepted Solution

cm_processes question

My understanding of the cm_processes tmpfs is that it is for issues on systems where /var is a no ext mount. We are running on RHEL 6.5 and /var is ext4. Is there a way to prevent CM from mounting this filesystem or, if not, adjusting its size? 

 

Thanks

Cloudera Employee
Posts: 23
Registered: ‎07-19-2013

Re: cm_processes question

Hi Greg,

 

It's required for distros where /var/run is mounted noexec but we use it unconditonally so that the Agent is operating in a consistent environment across all distros, and certain bits of agent functionality take advantage of this (such as our logic for cleaning out /var/run/cloudera-scm-agent, which unmounts and remounts the tmpfs).

 

What is your concern? Do you have a particular problem you are trying to solve?

 

Thanks,

Explorer
Posts: 17
Registered: ‎11-15-2013

Re: cm_processes question

Our OS team was asking about this because they saw the tmpfs filesystem allocated to 50% of memory. We weren't able to find a lot of documentation on it and were trying to determine if it was necessary and if so why. This has not caused any issues. I will pass the information along. Thanks.

Cloudera Employee
Posts: 23
Registered: ‎07-19-2013

Re: cm_processes question

A tmpfs will default to a max size of 50% of physical RAM but this space is not allocated until its used, and tmpfs will be paged out to swap if there is memory pressure.

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